From: "Herman J. Woltring" Subject: SCI: Dutch perception research Date: Thu, 26 Mar 92 12:35 MET TO: Bob Jacobson, moderator sci.virtual-worlds CC: Charles de Weert, NICI/KUN Biomch-L moderators Bob, Thanks for your enthusiastic note. As regards Biomechanics, we have a long tradition -- going back to, the work in Leyden/NL by the Dane Niels Stensen (or Nicolaus Steno, a bishop) in the 17th century and by Herman Boerhaave whose 1703 "Oratio de Usu Ratiocinii Mechanici in Medicina" was a laudatio on the utility of mechanics in a time that chemical approaches prevailed in Medicine. Steno used mechanical methods to describe the action of muscles. He thought that they were inflated during action; only recently, a Dane on sabbatical at the Mayo Clinic used MRI to show that muscle volume during contraction does not significantly change. While Boerhaave's lecture was largely concerned with fluid biomechanics, his starting words were also concerned with solid bodies: "Those who estimate the corporal forces from mass, shape and velocity, either theoretically or by experimental observation by means of the methods of Geometry are called Mechanicians." Interestingly, getting acceleration from velocity is an ill-posed problem, so Boerhaave was quite right in using the word `estimate'; various translators who may not have liked the fuzziness of this term opted for the word `calculate'. Well, if we could, indeed, reliably calculate forces in Biomechanics, there would be no Biomechanics -- Jan Jan- sen, a professor of fundamental mechanics here at Eindhoven University of Tech- nology is fond of saying that Biomechanics is just very difficult mechanics. The reappointment of Rik Huiskes, co-editor of the Journal of Biomechanics, a mechanical engineer from Jansen's group, as a professor of orthopaedic bio- mechanics in Nijmegen is another point of interest: his chair is supported by the Dutch Orthopaedic Society. Charles de Weert here at NICI (Nijmegen Institute for Cognition Research and Information Technology) kindly provided this morning the following comments on Dutch perception research: Herman, This question cannot be replied easily, but [Bob Jacobson] is right if he observes that the density of perception researchers in The Netherlands is larger than anywhere else in the world. Also, The Netherlands are unique in that much of that research is done by physicists [like Charles] and engineers; elsewhere, that is often not the case. There is a long tradition in perception. However, I don't think that this is related to the old masters, not to the inventor of the microscope (Anthony van Leeuwenhoek), or to the man who published theories about light (Huygens). In all cases one might mention other countries with at least equally famous investigators. During the previous century, the research by Donders (an ophthalmologist) provided an important impulse to experimental psychological research. In visual perception, Zwaardemakers (also an physiologist or ophthalmologist, I believe) at the start of the present century was important, and later, the work of Hessel de Vries (biophysics, Groningen) on threshold [subliminal?] perception was very influential. He showed that the sensitivity of the visual system allows more or less to `see' one to two quantums. This work was continued by Bouman (Institute for Perception Research, Soesterberg and Medical Physics, Utrecht) who produced a whole army of pupils who are now populating the universities. In the auditive domain, something similar might be told, perhaps. Regards, I look forward to your announcement of Biomch-L on sci.virtual-worlds. Herman J. Woltring (Biomch-L) Eindhoven/Nijmegen, The Netherlands